Eur. Phys. J. A 16, 599-601 (2003)
DOI: 10.1140/epja/i2002-10128-3

UCN production in superfluid helium

W. Schott¹, J.M. Pendlebury², I. Altarev¹, S. Gröger¹, E. Gutsmiedl¹, F.J. Hartmann¹, S. Paul¹, G. Petzoldt¹, P. Schmidt-Wellenburg¹ and U. Trinks<sup>1

1</sup>  Physik-Department E18, TU- München, D-85747 Garching, Germany
²  School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton, Sussex, BNI 9QJ, UK

wschott@e18.physik.tu-muenchen.de

(Received: 28 March 2002 / Revised version: 11 November 2002 / Published online: 11 March 2003)

Abstract
Ultra-cold neutrons (UCN) are produced in superfluid helium by single- and multi-phonon excitation. The UCN production rate density via multiphonons can be larger than that by one-phonon excitation being due to the dependence of the incident neutron spectral flux density on the wavelength .

PACS
78.70.Nx - Neutron inelastic scattering.
67.20.+k - Quantum effects on the structure and dynamics of nondegenerate fluids (e.g., normal phase liquid ).
61.12.Ex - Neutron scattering techniques (including small-angle scattering).
29.25.Dz - Neutron sources.

© Società Italiana di Fisica, Springer-Verlag 2003